The present invention refers to a plate package for a heat exchanger device including a tank, which forms a substantially closed inner space and which includes an inner wall surface facing the inner space, wherein the tank is arranged to be provided in such a way that a sectional plane, which extends through the plate package and the inner space of the tank, is substantially vertical, wherein the plate package is arranged to be provided in the inner space and includes heat exchanger plates provided adjacent to each other, wherein each heat exchanger plate has a main extension plane and is provided in such a way that the extension plane is substantially perpendicular to said sectional plane, wherein the heat exchanger plates form first plate interspaces, which are substantially open to the inner space and arranged to permit circulation of said medium from the lower part space upwardly to the upper part space, and second plate interspaces, which are closed to the inner space and arranged to permit recirculation of a fluid for evaporating the medium, wherein the first plate interspaces in an upper portion of the plate package form outlet channels for the medium, wherein each heat exchanger plate includes a first porthole and a second porthole and wherein the first portholes form an inlet channel for said fluid to the second plate interspaces and the second portholes form an outlet channel for said fluid from the second plate interspaces.
It is known to use such plate packages in heat exchanger devices for evaporating various cooling medium such as ammonium, freons etc, in applications for generating cold, for instance. The evaporated medium is then conveyed from heat exchanger device to a compressor and the compressed gaseous medium is thereafter condensed in a condenser. Thereafter the medium is permitted to expand and is then recirculated to the heat exchanger device. In such applications, it is important that the evaporation is complete and that no liquid is still present in the medium when it is supplied to the compressor, since the latter then may be damaged. In order to solve this problem, it is known to provide a liquid separator in the heat exchanger device in the proximity of the outlet for the medium. Such a liquid separator is disclosed in EP-B1-758 073, for instance.
This document discloses a heat exchanger device including a tank, which forms a substantially closed inner space and which has an inner wall surface facing the inner space. The tank includes an inlet for the supply of a medium in a liquid state and an outlet for discharging the medium in a gaseous state. The inner space defines a first lower part space for the medium in the liquid state and a second upper part space for the medium in the gaseous state. A plate package is provided in the inner space and includes heat exchanger plates provided against to each other. The heat exchanger plates form first plate interspace, which are open towards the inner space and arranged to permit recirculation of said medium from the first space upwardly towards the second space, and second plate interspaces, which are closed towards the inner space and arranged to permit recirculation of a fluid for evaporating the medium. The first plate interspaces form channels for said medium, which extend substantially straight upwardly along their whole length. Above plate package, a liquid separator is provided in such a way that substantially the whole quantity of the medium flowing upwardly from the plate package will hit the liquid separator and flow through the same, wherein possible remaining liquid is caught by the liquid separator and recirculated to the first lower part space.
WO97/45689 discloses an example of another heat exchanger device for an evaporator. The heat exchanger device includes a tank housing a plate package and a liquid separator in an upper part of the tank.
The disadvantage of such separate liquid separators is that they require space in the heat exchanger device. Such separators also increase the complexity and thus result in higher costs for manufacturing the device.
U.S. Pat. No. 3,538,718 discloses another heat exchanger device for cooling a fluid through evaporation of a liquid in a tank. The fluid is conveyed through a heat exchanger which is completely submerged in the liquid present in the tank. When the fluid is cooled, the liquid will be evaporated and the evaporated medium rises upwardly in the tank and is discharged via an outlet conduit. In this document, it is stated that the possible remaining liquid in the evaporated medium will be separated and recirculated to the liquid in the lower part of the tank.